title: A comparative study of two methods of optic disc evaluation in patients of glaucoma.
abstract: BACKGROUND
  Glaucoma is a progressive disorder and requires serial evaluation in order to monitor disease progression and optimize therapy.
  
  
  OBJECTIVE
  The objective of this study was to determine the correlation between each of cup/disc (C/D) ratio and the disc damage likelihood scale (DDLS) with retinal nerve fiber layer (RNFL) and global indices in Humphrey field analyzer II (HFA II).
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  A total of 50 patients diagnosed with primary open angle glaucoma were examined to grade DDLS score and C/D ratio. The average (avg) RNFL was obtained using the Fast RNFL protocol on optical coherence tomography (OCT) (4.0.2 Carl Zeiss). HFA II Swedish Interactive Threshold Algorithm Standard 24-2 visual fields were obtained within 1 month of clinical examination. The correlation of C/D ratio with avg RNFL thickness, Mean deviation and Pattern standard deviation was calculated by Pearson correlation coefficient (r). Similar coefficients were obtained for DDLS.
  
  
  RESULTS
  The P value for the difference in the r between C/D ratio with RNFL (-0.628) and DDLS with RNFL (-0.8369) was significant (P < 0.01) when correlation of C/D, DDLS with RNFL was considered.
  
  
  CONCLUSIONS
  The DDLS shows stronger correlation with structural changes in OCT than C/D ratio. The disc diameter and rim width increases the value of clinical optic disc examination.
authors.affiliation: Department of Ophthalmology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Chandra
authors.forename: Arun Kumar
authors.initials: AK
authors.lastname: Bandyopadhyay
authors.forename: Gautam
authors.initials: G
authors.lastname: Bhaduri
keywords: Cup/disc ratio; disc damage likelihood scale; retinal nerve fiber layer thickness; visual field